2017: MODFLOW & More, Scientific Advisory Committee Member
2015: MODFLOW & More, Scientific Advisory Committee Member
2012-: Scientific Director, Centre for High-Performance Scientific Computing in Terrestrial Systems, Geoverbund ABC/J
2012-2014: Water Resources Research, Associate Editor
Integrated Hydrologic Model Intercomparison Workshop, Phase 2, Organizer
2011-2013: AGU Fall Meeting Program Committee Member, Hydrology
2011: Integrated Hydrologic Model Intercomparison Workshop, Phase 1, Co-Organizer
2011: MODELCARE, Scientific Advisory Board Member
2011: MODFLOW & More, Scientific Advisory Committee Member
Dec. 2010: AGU, Session on Patterns in Soil Vegetation Atmosphere Systems
2010-2013: Computers & Geosciences, Associate Editor
Nov. 2009: Vadose Zone Journal, Guest Editor
Dec. 2009: AGU, Session on Advances in Data Acquisition and Integration into Hydrologic Models
Dec. 2009: AGU, Session on Patterns in Soil Vegetation Atmosphere Systems
Jun. 2009: Scientific Committee, International Workshop, SFB/TR32
Jun. 2009: SIAM, Session on Computational Approaches to Coupled Modeling
Jun. 2009: SIAM, Session on Patterns in Soil Vegetation Atmosphere Systems
Apr. 2009: EGU, Session on Patterns in Soil Vegetation Atmosphere Systems
since 2009: Reviewer for NWO and DFG
Dec. 2007: AGU, Session on Interactions of the Groundwater Land Surface Atmosphere System
2005-2010: Groundwater Technical Committee, AGU
since 2003: Reviewer for international scientific journals